[Updated with video, below] We already know that 3D-printing has revolutionized the way we can make everyday objects from Lego pieces, to guitars, and from car bodies to artificial livers. But the scale of this change could be much, much bigger if the "printers" themselves scale up enough to incorporate structures as large as airplanes.

Bastian Schaefer, a cabin engineer with Airbus, has been working for the last two years on a concept cabin that envisions what the future of flight would look like from the passenger's perspective. From that came a radical concept: build the aircraft itself from the ground up with a 3D printer that's very large in deed, ie. as big as an aircraft hangar. That probably sounds like a long shot, since the biggest 3D printers today are about the size of a dining table. But the Airbus design comes with a roadmap, from 3D-printing small components now, through to the plane as a whole around 2050.

Why use 3D printing at all? Airbus parent EADS has been looking into using the process, known as additive layer manufacturing, for making aircraft for some time because it's potentially cheaper, and can result in components that are 65% ligher than with traditional manufacturing methods. Airbus' concept plane is also so dizzyingly complicated that it requires radical manufacturing methods: from the curved fuselage to the bionic structure, to the transparent skin that gives passengers a panoramic view of the sky and clouds around them.

"It would have to be about 80 by 80 meters," said Schaefer of the eventual, yet-to-be-created 3D printer. "This could be feasible."

UPDATE - Here's a video produced at this year's Farnborough Air Show, with further details on the sustainable, high-tech features of the concept plane:

3D printing technology has been around for a while and there are plenty of innovators pushing it in extraordinary ways. Some of the biggest structures have come from Enrico Dini, the man behind British company Monolite UK, who has worked for years using 3D printing technology to mould sand and an inorganic binder into large, house-like structures. Dini has claimed that his 3D printer, known as the D-Shape, is the largest in the world.

Among the biggest challenges in scaling up 3D printing are money and regulation. Dini struggled to finance his large-scale printing projects because of the global financial crisis; his story is told in the forthcoming documentary "The Man Who Prints Houses."

Airbus meanwhile needs its designs to pass through stringent aircraft regulations before it can use the process to make plane components. One reason to start small: by the end of this year Airbus will have updated certain cabin brackets for the A380, making its super jumbo the company's first commercial plane to use 3D-printed components. New models of Airbus' Eurofighter Typhoon, a military jet, already contain non-structural parts of its air-conditioning unit that have been 3D printed, Schaefer said.

Airbus cabin designer Bastian Schaefer with a display of his 3D-printed concept plane at the TED Global conference in June 2012.

Another challenge is in incorporating the right materials. This Airbus concept plane's bionic structure requires materials that aren't available yet, such as strong-yet-transparent aluminum for the fuselage, certain biopolymers and other materials strengthened by carbon nano tubes.

But here is where 3D printers come in again. There is said to be just one 3D printer in the world that can print with multiple materials at the same time, made by a private Israeli company called Objet. David Benjamin, a partner at New York architecture firm The Living, says multi-material printers like Objet's can allow designers to experiment with different materials.

"You can dial in the different elasticity properties of an object, different color properties, or a continuous piece of material that has different properties over the piece," said Benjamin, who held sample, translucent slabs of plastic that were flexible in certain parts, and which had been created with customized Autodesk software and a 3D printer. "Certain parts of an airplane may need to be strong and flexible," he said, and a 3D printer could create a single object that was "strong just where it needed to be strong, or light where it needed to be light."

David Benjamin of The Living demonstrates a sample of 3D-printed plastic with a biopolymer "webbing."

If you imagine cake icing being squeezed through a tube, then a nozzle, this is not far off how 3D printing works, except the that the tube is moving on an X, Y an Z axis. Combining materials is a matter of using two nozzles together, for instance bonding aluminum to polyurethane in a single run.

"It's not theoretically impossible," said Benjamin, who specializes in combining synthetic biology with architectural design. "You can design new products that are not all solid or all aluminum, but a composite material. You're designing new substances."

The biggest challenge is size though, Benjamin said. If you can get a large enough room and a large enough gantry to move the nozzles -- known technically as extruders -- like a very precise version of the apparatus used to move shipping containers, you could make a 3D printed version of anything. The Objet printer is itself limited in scale, with printed objects no taller than two feet, Benjamin added.

EADS has been experimenting with 3D printing and famously printed an "Airbike" last year. Schaefer, who has been with Airbus for six years, started working on the transparent concept cabin project around the same time as the Airbike project in 2010, calling on colleagues from different departments at Airbus. "We have an opportunity to do something different," he told them.

He and other industrial designers, tech- and trend-scouts started brainstorming and came up with the current, 3D printed concept design. He has around 10 people working on the project with him, including industrial designers and tech scouts, all trying to push the technology forward.

"Now we'd like to create even bigger parts in the mid-term up to 2013," said Schaefer. "Printed components of a seat or other structural components inside the cabin, and we have 20 years to scale this up." 3D printing needs the push. The technology is more than over 20 years old, but it could be at least another 20 before we see it on the scale of what Bastian and others are foreseeing.

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